1. Field of the Invention
The present invention relates to a sliding door device. This application claims priority from Japanese Patent Application No. 2010-032671, filed on Feb. 17, 2010, the content of which is incorporated herein by reference.
2. Description of Related Art
In an air conditioner for a vehicle, as a damper device for adjusting the aperture ratio of an opening (opening for heating flow passage and opening for ventilation) through which an air flow cooled by an evaporator passes, a configuration including a sliding door device that slidably moves a sliding door using a rack and pinion scheme is known.
In the air conditioner for a vehicle, the sliding door is housed inside a frame case, and a pair of curved guide grooves for slidably supporting the sliding door is provided inside the frame case.
In addition, in Japanese Unexamined Patent Application, First Publication No. 2009-274708, when assembling the air conditioner for a vehicle, the sliding door provided in the frame case is housed inside the frame case while being slidably moved along the guide grooves by inserting the sliding door in a sliding door-insertion opening.
However, in the sliding door device that slidably moves the sliding door using the rack and pinion scheme described above, as shown in Japanese Unexamined Patent Application, First Publication No. 2009-274708, a pinion gear is engaged with a rack gear formed in the sliding door to thereby be rotatably driven, and thereby the sliding door is slidably moved.
To accurately adjust the position of the sliding door with respect to the rotation angle of the pinion gear, it is necessary to accurately adjust, in advance, the engagement position between the pinion gear and the rack gear in the rotation direction of the pinion gear. For this, in the conventional air conditioner for a vehicle, as shown in Japanese Unexamined Patent Application, First Publication No. 2009-274708, a thick tooth having a width, along the sliding direction, greater than those of other teeth (standard tooth) is provided at one side of the extension direction of the rack gear, and a large tooth groove that is engaged with the thick tooth is provided in the pinion gear. Due to this configuration, the thick tooth is engaged with the large tooth groove when inserting the sliding door into a guide portion, thereby adjusting the engagement position between the pinion gear and the rack gear.
However, in the air conditioner for a vehicle using this configuration, when the thick tooth of the rack gear is not smoothly engaged with the large tooth groove of the pinion gear when inserting the sliding door into the guide portion, the sliding door cannot be securely housed inside the frame case. In this case, it is difficult to engage the pinion gear and the rack gear in the exact engagement position.
In addition, in the conventional air conditioner for a vehicle as shown in Japanese Unexamined Patent Application, First Publication No. 2009-274708, when, during assembly, inserting the sliding door into the guide portion in a direction opposite to the original direction for inserting the sliding door into the guide portion, the sliding door is inserted from a side in which the thick tooth of the rack gear is not present. In this case, in a state in which whether the thick tooth of the rack gear and the large tooth groove of the pinion gear are engaged with each other is not verified, the sliding door is housed inside the frame case. However, when inserting the sliding door into the guide portion in the state in which the pinion gear and the rack gear are not accurately engaged with each other, the thick tooth of the rack gear is thrust into the tooth groove of the pinion gear, and thereby excessive force is exerted on the rack gear and the pinion gear. As a result, a positional deviation between the pinion gear and the rack gear is generated, and thereby the sliding door cannot be accurately slid.
To overcome these problems, when assembling the air conditioner for a vehicle, it is necessary to insert the sliding door to the guide groove in the correct direction in which the sliding door is originally intended to be inserted, based on accurate ascertainment by the operator of the direction of the sliding door. Due to this, an operation for determining the insertion direction of the sliding door is needed each time, causing an increased burden on the operator.
Furthermore, the operation for determining the insertion direction of the sliding door is not only required when assembling the air conditioner for a vehicle, but is also required even when assembling the sliding door device used for devices other than the air conditioner for a vehicle.